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APS – Ground-level power supply

APS is a service-proven power system for tramways which supplies electricity through a third rail at ground level and eliminates the need for catenaries, thus preserving the aesthetics of city centres and guaranteeing maximum safety.


A stand-alone or integrated solution

APS can be used as a single power supply source or as a complement to other systems, such as catenaries or back-up batteries.

Complete safety

As the tram passes, power is supplied to the conductive segments via coded radio dialogue between the tram and the ground.  Any segments not “covered” by the tram are not powered. The safety of the APS system has been proven through dedicated studies and confirmed by five certifying authorities including CERTIFER and STRMTG.

Service-proven solution

APS is in service in Bordeaux, Reims, Orleans, Angers and Tours and has been ordered by the cities of Dubai, Cuenca and Rio. To date, 352 Citadis trams equipped with APS have run over 20 million kilometres with an availability rate of over 99.7%. 62km of single track are currently equipped with APS.

From kit delivery to integrated solutions

Alstom offers APS as an infrastructure kit in addition to a Citadis rolling stock contract or as part of a turnkey tramway system contract, guaranteeing an integrated solution for our customers. Alstom also offers APS as part of a modernisation programme.

Available in two versions

  • Standard APS dedicated to temperate climates
  • Tropicalized APS for extreme climatic conditions


  • Elimination of catenaries
  • Preservation of historic sites, trees along the track and the overall urban environment
  • Unlimited power supply (as opposed to power storage systems)
  • Compatibility with all types of road surfaces
  • Elimination of wayside masts, limiting footprint and allowing wider tram vehicles to circulate
  • Easy extension of the system if the line is extended
  • High availability for optimum operational performance due to the simplicity of the concept, inspired by power supply rails used in metros
  • Proven resilience, both in degraded mode and disrupted conditions of service (traffic jam at intersection for instance)
  • Total safety for passengers, pedestrians and road traffic

Catenary-free solutions for tramway systems